Connector systems of this type are known and universally used in various areas demanding very good qualities of precision and reliability.
General configurations of these systems comprise two tubular bodies forming a plug and socket arrangement, each of these plug and socket bodies being intended to be coupled to conductors for the transmission of electric, photonic or fluid signals, and the plug and socket bodies being for engagement into one another. Upon insertion of the plug body into the socket body a self-latching mechanism automatically locks the plug body in the socket body by mere pushing the plug body axially into the socket body. When required, the plug body is disengaged from the socket body by a straight axial pull on an outer release sleeve which initially allows unlocking of the self-latching mechanism and then withdrawal of the plug body out of the socket body. Accordingly, the connection between plug body and socket body cannot be broken by pulling on the cable containing the signal transmission conductors or any other component part of the plug and socket bodies other than the outer release sleeve.
In a well known of these connector systems, a plurality of peripheral elastic tongues are mounted on the plug body and each of said tongues bears on outwardly projecting latch whereby each said latches may resiliently move radially on the plug body. An outer sleeve slidably mounted on the plug body for axial movement therealong comprises an extension surrounding the peripheral elastic tongues and this extension has a plurality of transverse windows respectively placed over the projecting latches, whereby axial movement of the sleeve over the plug body causes the windows of the sleeve extension to act as ramps forcing the projecting latches radially and inwardly with respect to the plug body. The socket body comprises an inner circular groove for catching the projecting latches upon insertion of the plug body into the socket body. According to the general operation described hereabove, connection of the system is obtained by mere insertion of the plug body into the socket body, whereby the projecting latches radially contract to enter into the socket body and then expand into the catching groove thereof, thus locking the assembly of plug body and socket body. Disconnection of the system is obtained by axial pull on the outer sleeve the windows of which radially contract the projecting latches thereby allowing extraction thereof from the catching groove whereby the plug body may be withdrawn from the socket body.
Another of these connector systems, described in U.S. Pat. No. 3,160,457, comprises a plurality of peripheral elastic tongues with protruding latches mounted on a release sleeve slidably arranged over the plug body which carries a truncated cone ramp disposed under the latches. A release space is provided between the latches and the plug body. The socket body comprises an inner circular groove for catching the protruding latches upon insertion of the plug body into the socket body. Connection of the system is obtained by pushing the plug body into the socket body whereby the latches may contract in the release space and enter into the socket body and then expand into the catching groove. In that configuration, any pull on the plug body other than on the release sleeve results in the truncated cone ramp of the plug body further urging the latches in the catching groove of the socket body. Disconnection of the self-latching assembly is obtained by pulling the release sleeve whereby the latches may contract in the release space to allow withdrawal of the plug body from the socket body.
Still a further of these connector systems is described in FR-A-2159701. A plug body comprises a plurality of peripheral elastic tongues with inwardly projecting latches intended to engage an annular catching groove peripherally arranged on a socket body. A release sleeve is mounted for movement over the plug body and comprises at one end a bevelled portion orientated towards the inwardly projecting latches and capable of passing beneath them, and at the other end, a stop arrangement cooperating with a circlip mounted elastically on the plug member. The internal surface of the release sleeve is staged so as to block the inwardly projecting latches in the catching groove of the socket body when the stop arrangement is engaged on the circlip and to allow the latches to expand radially out of the catching groove when the stop arrangement is released from the circlip, which allows the bevelled portion of the release sleeve to pass beneath the latches to spread them radially apart and unlock the self-latching connection.
All these connector systems are definitely fail-proof with operators who know or can recognise that they have in hands a plug body or a socket body that are made to fit to one another whereby the connection can be secured either by inserting the plug body into the socket body or by engaging the socket body over the plug body. However, this is not necessarily the case in high stress or so-called blind conditions such as exist, for example, in military operation. A fail-proof connection cannot be assured if the operator may be puzzled by having in hand the plug body or the socket body. And that situation may be particularly acute where connection has to be made on loose cables.